This standard specifies the gravimetric method for determining the content of inorganic sulfate in various detergents1]. Other compounds that are usually present do not interfere with the determination results. GB/T 15817-1995 Gravimetric method for determining the content of inorganic sulfate in detergents GB/T15817-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of mineral sulfate content in detergents-Gravimetric method
GB/T 15817--1995
This standard is equivalent to the international standard ISO8214:1985 "Surface active agents - washing powder - Gravimetric method for determination of inorganic sulfate content". This standard does not adopt the Soxhlet extractor and filter porcelain crucible and their corresponding use procedures specified in ISO8214. The scope of application of this standard is expanded from washing powder to detergent. 1 Subject content and scope of application
This standard specifies the gravimetric method for determining the inorganic sulfate content in various detergents1. Other compounds that are usually present do not interfere with the determination results.
2 Reference Standards
GB/T13173.1 Method for Sample Splitting of Detergents3 Principle
Extract the test portion with ethanol to remove all ethanol solubles. When silicates are present, dehydrate and filter, then precipitate the sulfate present in the filtrate with barium chloride. Filter the precipitate, wash, burn at 900℃, and weigh.
4 Reagents
Only approved analytical reagents should be used during the analysis. Only distilled water or water of equivalent purity should be used. 4.1 Anhydrous ethanol (GB678).
4.2 Hydrochloric acid (GB 622).
4.3 Ammonia water (GB631).
4.4 Barium chloride (GB652), 100g/L solution. 4.5 Silver nitrate (GB670), 5g/L solution. 4.6 Methyl orange, 1g/L solution.
Instructions for adoption:
1 The name and scope of application of ISO8214 only indicate "washing powder", this standard is changed to "detergent", and the scope is expanded. Approved by the State Bureau of Technical Supervision on December 8, 1995 306
Implementation on August 1, 1996
5 Instruments 13
Ordinary laboratory instruments and:
5.1 Single-line volumetric flask, 500mL.
5.2 Oven, temperature controllable at 105±2℃. 5.3 Porcelain 2, 30mL.
GB/T 15817 -1995
5.4 High-temperature furnace, temperature controllable at 900±10℃. 6 Sampling
Prepare uniform samples for testing in accordance with GB/T13173.1. .7 Test Procedure
7.1 Test Portion
In a 250 mL beaker, weigh approximately 5 g of the laboratory sample to the nearest 0.001 g. 7.2 Removal of Organic Matter 37 bzxZ.net
Add approximately 120 mL of anhydrous ethanol (4.1) to the test portion (7.1). Cover with surface III, heat and stir with a glass rod, or heat and stir on a heated magnetic stirrer until the ethanol boils. Continue stirring and boiling for 5 min.
Allow the beaker to allow the insoluble matter to settle, and filter the ethanol phase through a medium-speed filter paper. Repeat the extraction as above with a new ethanol portion at least twice, still filtering with the same filter paper.
Add approximately 40 mL of hot ethanol (50-60°C) to the beaker containing the insoluble matter, break up any remaining lumps with a glass rod, and stir to wash. Allow the insoluble matter to settle, filter through the same filter paper, and repeat this operation twice. Pierce the bottom of the filter paper with a needle and wash the residue on the filter paper into the beaker containing the ethanol insoluble matter with about 50 mL of hot water (about 60°C). 7.3 Removal of silicates
Add 10 mL of hydrochloric acid (4.2) to the beaker, stir with a glass rod, and evaporate to dryness on a steam bath. Add 15-20 mL of water, stir and heat for 10 min. If there is no silica and insoluble matter, proceed as in 7.4. Otherwise, proceed as follows.
Add another 5 mL of hydrochloric acid (4.2), stir and evaporate to dryness as before. Dissolve the residue with water, add 5 mL of hydrochloric acid (4.2), stir, and evaporate to dryness for the third time. Place the beaker and the residue in an oven at 105 ± 2°C for 1 h. Add 50 mL of hot water and 5 ml of hydrochloric acid, and heat on a steam bath with intermittent stirring for 10 min.
Filter through a fast filter paper. Wash the residue four times with hot water, 30 mL of water each time. Note: The insoluble residue can be used to determine the total silica. For this purpose, the residue needs to be further transferred and washed. 7.4 Determination
Quantitatively transfer the filtrate and washing solution or the solution without silica and insoluble matter to a 500mL single-line volumetric flask. Dilute to the mark with distilled water and mix well. Use a pipette to transfer a full volume of the solution to a 250mL beaker. If the sulfate content of the sample is between 10% and 20%, take 100mL, or take a volume equivalent to the mass of sulfuric acid precipitate between 150 and 300mg. Instructions for use:
1] ISO)8214 also stipulates the use of Soxhlet extractors and glass extraction sleeves, which are not used in this standard. 2] ISO)8214 stipulates the use of platinum crucibles. This standard uses porcelain crucibles instead to meet the analysis needs. 3] ISO8214 stipulates two procedures for removing organic matter: Soxhlet extraction and extraction with ethanol in a beaker. This standard only uses one procedure and the amount of ethanol used is appropriately reduced.
GB/T 15817—1995
Add water to 100mL if necessary, add four drops of methyl orange solution (4.6) and neutralize with ammonia water (4.3). Add hydrochloric acid (4.2) until it is just acidic, and then add 5mL in excess. Heat to boiling and slowly add 5mL of fluoride solution (4.4) while boiling, cover the surface spot and boil slightly for 5min. Place on a steam bath at 70~80℃ for at least 1h or age overnight. Add a few drops of barium chloride solution to check whether the precipitation is complete. Decant the supernatant and filter it through slow ashless filter paper! Then wash the precipitate in the beaker with hot water and transfer it to the filter paper until a few drops of silver nitrate solution (4.5) are added to check that the washing liquid is free of chloride ions. Pre-burn the porcelain in a high-temperature furnace controlled at 900℃, and cool it in a desiccator and weigh it. Put the filter paper with the precipitate into the porcelain of known mass. Move it into a high-temperature furnace, dry the crucible and its contents at about 110°C, then gradually heat it to 300°C to completely carbonize the filter paper, then heat it to 900°C (or gradually heat it on an electric furnace to dry the crucible and its contents until they are completely carbonized, then move it into a 900°C high-temperature furnace) and burn it for 30 minutes, cool it in a dryer and weigh it accurately to 0.0001g. 8. Expression of results
8.1 Calculation method
The content of inorganic sulfate in the detergent, X, is expressed as the mass percentage of sodium sulfate and is given by the following formula: X(%) = m× 500×0. 608 6 × 100moxV
Where; m. —Mass of the test portion, 8,
-Mass of sulfuric acid precipitation, g;
V—Volume of the whole portion, mL,
0. 608 6-
8.2 Precision
Conversion factor of barium sulfate to sodium sulfate. When the sodium sulfate content X is 6%~～30% (m/m), the difference between the results of parallel determinations by the same analyst in the same laboratory should not exceed 0.10XV/2%. The difference between the results determined by different analysts in different laboratories should not exceed 0.20X1/2%. Instructions for use:
1] ISO8214 also stipulates that vacuum filtration should be performed using a P4 porcelain filter crucible (pore size 1.6～4μm). Additional instructions:
This standard is proposed by the China Light Industry Federation.
This standard is under the jurisdiction of the National Surfactant Detergent Standardization Center. This standard was drafted by the Nanjing Alkylbenzene Factory Research Institute. The main drafters of this standard are Zou Yourong and Gao Zhen.
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